As a conventional relay, there has been used a mechanical relay with a metal contact, and a contact type relay such as a mercury relay, a lead relay, and so forth.
A major problem with the relay is a service life of a contact. A relay long in service life, and highly reliable is much in demand in various sectors of the industry, however, the present situation is that a relay decisively meeting the demand is not available as yet. Meanwhile, the mercury relay is shunned by users because of problems of environmental pollution, and a high cost thereof although it has high reliability. Preceding Patent Documents concerning a mercury relay, and a semiconductor relay replacing a mercury relay, respectively, include the followings:
[Patent Document 1] JP 9-61275 A
[Patent Document 2] JP 11-74539 A
A technology disclosed in Patent Document 1 is concerned with an apparatus for detecting a drop in pressure of hydrogen gas sealed inside the mercury relay, and a technology disclosed in Patent Document 2 is concerned with the semiconductor relay wherein the product of an on-resistance at the time of conduction/shut-off of a contact, and capacitance at the time of shut-off/conduction of the contact is low, and a low on-resistance is achieved at a low capacitance between output terminals in a low voltage region, thereby enabling applications at a radio frequency to be developed.